【作者】 李玲；

【导师】 刁兆玉；

【作者基本信息】 山东师范大学 ， 物理化学， 2011， 硕士

【摘要】 本论文主要研究阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)分别与非离子表面活性剂十二烷基聚氧乙烯(9)醚(AEO9)和辛基苯酚聚氧乙烯(10)醚(TX-100)复配体系形成的微乳液的相行为等。用“鱼状”相图法研究CTAB/AEO9/醇/油/盐水和CTAB/TX-100/醇/油/盐水溶液微乳液体系的相行为和增溶性能;并考察盐水溶液、油、温度以及醇等不同因素对该体系中阳/非离子表面活性剂以固定摩尔比条件下相行为的影响;又用拟三元相图法研究CTAB/AEO9 (TX-100) /正丁醇/正辛烷/水(或盐水)溶液微乳液体系的相行为,并利用测量电导率的方法来研究形成微乳液的结构及其结构转变;并研究了制备新型复合材料Al2(WO4)3的前驱体的方法,从而为微乳液技术制备纳米颗粒提供一定的理论基础。论文包括以下四部分:一、绪论介绍了表面活性剂复配的意义和表面活性剂复配的各种类型;概述了微乳液的结构、性质,详细介绍了微乳液的形成机理:瞬时负界面张力理论、双重膜理论、几何排列理论、R比理论;综述了微乳液的表征方法和应用。最后总结了本论文的立题依据和主要研究内容。二、CTAB/AEO9复配表面活性剂体系中相微乳液相行为的研究利用ε-β“鱼状”相图法研究了十六烷基三甲基溴化铵(CTAB)/十二烷基聚氧乙烯(9)醚(AEO9)以不同摩尔比复配体系的中相微乳液的相行为。并对CTAB/AEO9复配体系讨论了电解质浓度、助表面活性剂、油相和温度等因素对该微乳液体系增溶能力的影响。1.从“鱼状”相图中可以清楚地观察到,随着醇浓度的增加的相转变WinsorⅠ→Ⅲ→Ⅱ。无论是向CTAB体系中加入少量的AEO9,还是向AEO9体系中加入少量的CTAB,CTAB/AEO9/油/醇/NaCl水溶液微乳液体系的增溶性能均比原来单一表面活性剂体系形成的微乳液的增溶性能有明显增强。2.无机盐氯化钠的加入更加促进体系中相微乳液的形成,随着水溶液中NaCl的质量分数的增加,体系形成单相微乳液所需的醇量(εE)减小,其增溶能力的顺序:10 % > 7.5 % > 5 % > 2.5 %。3.随着油分子碳链长度的增加,形成中相微乳液所需的醇和表面活性剂的量大幅度增加,而形成单相微乳液能力的顺序为:正己烷>正庚烷>正辛烷。4.不同的温度对CTAB/AEO9微乳液体系有不同程度的影响,其所形成微乳液体系的增溶能力顺序是:40℃> 50℃> 25℃> 30℃.5.助表面活性剂醇的碳链越长,形成的微乳液体系的增溶能力越大。三、CTAB/TX-100复配表面活性剂体系中相微乳液相行为的研究利用ε-β“鱼状”相图法研究了十六烷基三甲基溴化铵(CTAB)/辛基苯酚聚氧乙烯(10)醚(TX-100)微乳液体系的相行为。考察了氯化钠溶液浓度(5 %,7.5 %,10 %)、不同烷烃(正己烷,正庚烷,正辛烷)、短链醇(正丁醇,正戊醇)等因素对该体系微乳液增溶性能的影响。并比较了不同因素对CTAB/AEO9和CTAB/ TX-100微乳液体系影响。1.阳/非离子表面活性剂复配体系比单一表面活性剂体系形成的微乳液具有更强的增溶性能;2.由于无机盐氯化钠的加入更加促进体系中相微乳液的形成;3.随着油分子碳链长度的减少和助表面活性剂分子碳链长度的增加,越有利于微乳液的相转变。4.通过对CTAB/AEO9和CTAB/TX-100复配体系中形成中相微乳液的比较,不同因素对两种体系的影响趋势几乎是一致,但是相同条件下,CTAB/AEO9复配体系形成的中相微乳液的增溶能力较大。四、用电导率法研究混合表面活性剂体系中微乳液结构研究了CTAB/AEO9/正丁醇/正辛烷/水或盐水体系和CTAB/TX-100/正丁醇/正辛烷/水或盐水体系的拟三元相图,讨论了微乳液单相区的微观结构,并研究了在油包水微乳区制备Al2(WO4)3前驱物的方法。1. CTAB/AEO9/正丁醇/正辛烷/水体系形成的微乳液单相区比CTAB/TX-100/正丁醇/正辛烷/水体系形成的微乳液单相区稍小;无机盐电解质的加入使得两个体系所形成的微乳液单相区均减小。2.从CTAB/AEO9 (TX-100)/正丁醇/正辛烷/水体系微乳液的电导率曲线可以识别微乳的三种微结构,即油包水、水包油及二连续型。开始体系电导率随含水量增加而呈直线上升,而后增加缓慢达到最大值,之后又随着含水量的进一步增加,电导率值开始下降。3.从CTAB/AEO9 (TX-100)/正丁醇/正辛烷/盐水体系的电导率曲线可以看到,在含水量较少时,电导率随盐水含量的变化趋势与在纯水体系中的变化趋势相同,随着盐水含量的增加又呈非线性增加,最后又随着盐水含量的增加而线性增大。因此,可以根据盐水体系中微乳液电导率曲线的两个折点,将整个微乳液单相区划分为W/O、B.C和O/W区。更多还原

【Abstract】 The phase behavior for the systems of Cetyltrimethylammonium bromide (CTAB)/poly- ethyleneglycol (9) monododecyl ether (AEO9) and CTAB/Octylphenol polyoxyethylene-10- ether (Triton X-100) have been studied in this thesis. The middle-phase behavior and solubili -zation for the microemulsions systems of CTAB/AEO9/alcohols/oils/brine and CTAB/ TX-100/ alcohols/oils/brine have been studied withε-βfishlike phase diagram method, and the effects of different alcohols, oils, temperature and inorganic salt (NaCl) on the middle-phase behavior of microemulsion formed by composile CTAB/AEO9 (TX-100) microemulsions systems were also investigated systematically. The phase diagrams of the pseudo-ternary-component of CTAB/ AEO9 (TX-100)/n-butanol/n-octane/water or brine systems were studied by dilution method, and then the microstrctures of microemulsions were determined through conductance technique, and the method of preparing Al2(WO4)3 precursor in the W/O microemulsion region was studied. Which provide valuable theoretical basis for preparing nanoparticles through microemulsion technology. This thesis contains four chapters:Chapter I. IntroductionSignificance and various types of mixed surfactants systems were introduced. The structure and characteristic of microemulsion were also overviewed. And the formation mechanism of microemulsion was introduced in detail: Instantaneous negative interfacial tension theory, Double film theory, Geometry theory, R ratio theory. The application and research methods of microemulsion were investigated. At last, the legislative basis and the contents of this thesis were summarized.Chapter II. Studies on the middle phase behavior of the microemulsion formed by CTAB/AEO9 mixed surfactants systemsThe middle-phase behavior and solubilization for the microemulsion system of cetyltrimethy -lammonium bromide (CTAB) and poly-ethyleneglycol (9) monododecyl ether (AEO9) have been studied withε-βfishlike phase diagram method. The effects of different alcohols, oils, temperature and inorganic salt (NaCl) on the middle-phase behavior of microemulsion formed by composile CTAB/AEO9 systems were also investigated systematically.1. Fromε-βfishlike phase diagrams, the microemulsion phase inversion Winsor I→III→II was observed with the increase in the alcohol concentration. Whether a small amount of AEO9 added into the CTAB system, or a small amount of CTAB added into the AEO9 system, the solubilization of the microemulsion formed by mixed cationic and nonionic surfactants is more effective than the single surfactant system.2. With the increase in the mass fraction of NaCl in aqueous phase, the amount of alcohol (εE) used to form single phase microemulsion decreases, and the solubilization power of the microemulsion system increases. The order of the solubilization power is 10 % > 7.5 % > 5 % > 2.5 %.3. The longer the carbon chain length of alkane is, the more alcohol needed to form middle phase microemulsion is. The solubilization power order is n-hexane > n-heptane > n-octane.4. The temperature has some effect on solubilization power of the microemulsion systems formed by CTAB/AEO9 microemulsion systems. The order of the solubilization power is 40℃> 50℃> 25℃> 30℃.5. The ability to form middle phase microemulsion and the solubilization power increase with its carbon chain length increases.Chapter III. Studies on the middle phase behavior of the microemulsion formed by CTAB/TX-100 mixed surfactants systemsThe middle-phase behavior and solubilization for the system of cetyltrimethylammonium bromide (CTAB) and Octylphenol polyoxyethylene-10-ether (Triton X-100) have been studied withε-βfishlike phase diagram method. The effects of different alcohols (n-butanol, n-propanol), oils (n-hexane, n-heptane, n-octane) and inorganic salt (NaCl: 5 %, 7.5 %, 10 %) on the middle-phase behavior of microemulsion formed by composile CTAB/TX-100 systems were also investigated systematically. Finally, we compared the effects of different factors on the phase behavior of microemulsions formed by CTAB/AEO9 and CTAB/TX-100 systems.1. The solubilization of the microemulsion formed by mixed cationic and nonionic surfactants is more effective than the single surfactant system.2. Adding inorganic salt (NaCl) facilitates the microemulsion inversion.3. The oils with shorter carbon chain lengths and the alcohols with longer carbon chain lengths are of higher solubilization power of their microemulsions systems.4. Comparing the effects of different factors on the phase behavior of microemulsions formed by CTAB/AEO9 and CTAB/TX-100 systems, we can see that the solubilization of CTAB/AEO9 microemulsion is higher than that of CTAB/TX-100 system under the same conditions, while the impact on the two systems with the factors are almost the same. Chapte IV. Studies on the structure of microemulsion formed by the mixed surfactants systems by conductivityThe phase diagrams of the pseudo-ternary-component of CTAB/AEO9/n-butanol/n-octane/ water and CTAB/TX-100/n-butanol/n-octane/water systems were studied by dilution method. The microstrctures of microemulsions were determined through conductance technique, and the method of preparing Al2(WO4)3 precursor in the W/O microemulsion region was studied.1. The single-phase microemulsion region of CTAB/AEO9/n-butanol/n-octane/water system is larger than that of CTAB/TX-100/n-butanol/n-octane/water system, the addition of inorganic salts reduced the single-phase microemulsion of the two systems.2. Three types of microemulsion microstructure can be identified from the conductivity curves of CTAB/AEO9 (TX-100)/butanol/octane/water microemulsion systems: W/O, O/W and BC. Conductivity increases linearly with the increase of water content at the beginning, and then increased slowly to reach the maximum, the conductivity begin to decline with the further increasing of the water content.3. From the conductivity curves of CTAB/AEO9 (TX-100)/butanol/octane/brine microemulsion systems, we can see that conductivity of the brine system changes almost the same as that of the water systems with a small amount of water. And then conductivity showed a nonlinear increase with the increase of brine. Finally, conductivity increases linearly. Therefore, the whole single- phase microemulsion area is divided into W/O, BC and O/W based on the two turning point in the electrical conductivity curve of brine microemulsion systems .更多还原